[ISSUE #9308]For the orchestration of configuration filters, there are the following areas that can be optimized #9309

client/src/main/java/com/alibaba/nacos/client/config/filter/impl/ConfigFilterChainManager.java

@@ -36,12 +36,27 @@ public class ConfigFilterChainManager implements IConfigFilterChain {
 
  private final List<IConfigFilter> filters = new ArrayList<>();
 
+ private IConfigFilterChain filterChain;
+
  public ConfigFilterChainManager(Properties properties) {
  ServiceLoader<IConfigFilter> configFilters = ServiceLoader.load(IConfigFilter.class);
  for (IConfigFilter configFilter : configFilters) {
  configFilter.init(properties);
  addFilter(configFilter);
  }
+ buildConfigFilterChain();
+ }
+
+ /**
+ * Build ConfigFilterChain.
+ */
+ public void buildConfigFilterChain() {
+ filterChain = new EmptyFilterChainNode();
+ for (int i = filters.size() - 1; i >= 0; i--) {
+ final IConfigFilter filter = filters.get(i);
+ final IConfigFilterChain next = filterChain;
+ filterChain = new FilterChainNode(filter, next);
+ }
  }
 
  /**
@@ -74,26 +89,31 @@ public synchronized ConfigFilterChainManager addFilter(IConfigFilter filter) {
 
  @Override
  public void doFilter(IConfigRequest request, IConfigResponse response) throws NacosException {
- new VirtualFilterChain(this.filters).doFilter(request, response);
+ filterChain.doFilter(request, response);
  }
 
- private static class VirtualFilterChain implements IConfigFilterChain {
+ private static class FilterChainNode implements IConfigFilterChain {
 
- private final List<? extends IConfigFilter> additionalFilters;
+ private final IConfigFilter filter;
 
- private int currentPosition = 0;
+ private final IConfigFilterChain next;
 
- public VirtualFilterChain(List<? extends IConfigFilter> additionalFilters) {
- this.additionalFilters = additionalFilters;
+ public FilterChainNode(IConfigFilter filter, IConfigFilterChain next) {
+ this.filter = filter;
+ this.next = next;
  }
 
  @Override
- public void doFilter(final IConfigRequest request, final IConfigResponse response) throws NacosException {
- if (this.currentPosition != this.additionalFilters.size()) {
- this.currentPosition++;
- IConfigFilter nextFilter = this.additionalFilters.get(this.currentPosition - 1);
- nextFilter.doFilter(request, response, this);
- }
+ public void doFilter(IConfigRequest request, IConfigResponse response) throws NacosException {
+ filter.doFilter(request, response, next);
+ }
+ }
+
+ private static class EmptyFilterChainNode implements IConfigFilterChain {
+
+ @Override
+ public void doFilter(IConfigRequest request, IConfigResponse response) throws NacosException {
+
  }
  }
 

client/src/test/java/com/alibaba/nacos/client/config/filter/impl/ConfigFilterChainManagerTest.java

@@ -43,11 +43,11 @@ public MyIConfigFilter(String name, int order) {
  this.name = name;
  this.order = order;
  }
-
+  
  @Override
  public void init(IFilterConfig filterConfig) {
  }
-
+  
  @Override
  public void init(Properties properties) {
  }
@@ -100,6 +100,7 @@ public void testAddFilterOrder() throws NacosException {
  configFilterChainManager.addFilter(filter2);
  configFilterChainManager.addFilter(filter1);
  configFilterChainManager.addFilter(filter3);
+ configFilterChainManager.buildConfigFilterChain();
 
  ConfigRequest configRequest = new ConfigRequest();
 
@@ -127,6 +128,7 @@ public void testAddFilterNotRepeat() throws NacosException {
  configFilterChainManager.addFilter(filter2);
  configFilterChainManager.addFilter(filter1);
  configFilterChainManager.addFilter(repeatFilter);
+ configFilterChainManager.buildConfigFilterChain();
 
  ConfigRequest configRequest = new ConfigRequest();
  configFilterChainManager.doFilter(configRequest, new ConfigResponse());
@@ -135,4 +137,28 @@ public void testAddFilterNotRepeat() throws NacosException {
 
  Assert.assertEquals(2, configContext.getParameter("filterCount"));
  }
+
+ @Test
+ public void testSpiFilterNodeChain() throws NacosException {
+ final ConfigFilterChainManager configFilterChainManager = new ConfigFilterChainManager(new Properties());
+
+ configFilterChainManager.doFilter(new ConfigRequest(), new ConfigResponse());
+ }
+
+ @Test
+ public void testAddFilterNodeChain() throws NacosException {
+ final ConfigFilterChainManager configFilterChainManager = new ConfigFilterChainManager(new Properties());
+
+ MyIConfigFilter filter1 = new MyIConfigFilter("filter1", 1);
+ MyIConfigFilter filter2 = new MyIConfigFilter("filter2", 2);
+ MyIConfigFilter filter3 = new MyIConfigFilter("filter3", 3);
+
+ configFilterChainManager.addFilter(filter2);
+ configFilterChainManager.addFilter(filter1);
+ configFilterChainManager.addFilter(filter3);
+ // When an external filter is added via the addFilter() method, the responsibility chain only needs to be rebuilt, which in fact is rare.
+ configFilterChainManager.buildConfigFilterChain();
+
+ configFilterChainManager.doFilter(new ConfigRequest(), new ConfigResponse());
+ }
 }

client/src/test/java/com/alibaba/nacos/client/config/filter/impl/ConfigFilterChainTest.java

@@ -27,6 +27,8 @@ public void testConfigFilterChain() {
  ConfigFilterChainManager configFilterChainManager = new ConfigFilterChainManager(null);
  configFilterChainManager.addFilter(new DemoFilter1());
  configFilterChainManager.addFilter(new DemoFilter2());
+ configFilterChainManager.buildConfigFilterChain();
+
  ConfigRequest configRequest = new ConfigRequest();
  ConfigResponse configResponse = new ConfigResponse();
  try {